package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.hmdp.dto.Result;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.RedisIdWoker;
import com.hmdp.utils.UserHolder;
import lombok.extern.slf4j.Slf4j;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.connection.stream.*;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.time.Duration;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
@Slf4j
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {

    @Resource
    private ISeckillVoucherService seckillVoucherService;
    @Resource
    private RedisIdWoker redisIdWoker;
    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Resource
    private RedissonClient redissonClient;

    private static final DefaultRedisScript<Long> SECKILL_SCRIPT;
    static {
        SECKILL_SCRIPT = new DefaultRedisScript<> ();
        SECKILL_SCRIPT.setLocation (new ClassPathResource ("seckill.lua"));
        SECKILL_SCRIPT.setResultType (Long.class);
    }
    private static final ExecutorService SECKILL_ORDER_EXECUTOR = Executors.newSingleThreadExecutor ();
    @PostConstruct
    private void init(){
        SECKILL_ORDER_EXECUTOR.submit (new VoucherOrderHandler ());
    }
    String queueName = "stream.orders";
    private class VoucherOrderHandler implements Runnable{
        @Override
        public void run() {
            while (true){
                try {
                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream ().read (
                            Consumer.from ("g1", "c1"),
                            StreamReadOptions.empty ().count (1).block (Duration.ofSeconds (2)),
                            StreamOffset.create (queueName, ReadOffset.lastConsumed ())
                    );
                    if (list == null || list.isEmpty ()){
                        continue;
                    }
                    MapRecord<String, Object, Object> record = list.get (0);
                    Map<Object, Object> values = record.getValue ();
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap (values, new VoucherOrder (), true);
                    handleVoucherOrder (voucherOrder);
                    stringRedisTemplate.opsForStream ().acknowledge (queueName,"g1",record.getId ());
                } catch (Exception e) {
                    log.error ("处理订单异常",e);
                    handlerPendingList();
                }
            }
        }
    }

    private void handlerPendingList () {
        while (true){
            try {
                List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream ().read (
                        Consumer.from ("g1", "c1"),
                        StreamReadOptions.empty ().count (1),
                        StreamOffset.create (queueName, ReadOffset.from("0"))
                );
                if (list == null || list.isEmpty ()){
                    break;
                }
                MapRecord<String, Object, Object> record = list.get (0);
                Map<Object, Object> values = record.getValue ();
                VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap (values, new VoucherOrder (), true);
                handleVoucherOrder (voucherOrder);
                stringRedisTemplate.opsForStream ().acknowledge (queueName,"g1",record.getId ());
            } catch (Exception e) {
                log.error ("处理pending-list订单异常",e);
                try {
                    Thread.sleep (20);
                } catch (InterruptedException ex) {
                    ex.printStackTrace ();
                }
            }
        }
    }
//    private ArrayBlockingQueue<VoucherOrder> orderTasks = new ArrayBlockingQueue<>(1024*1024);
//    private class VoucherOrderHandler implements Runnable{
//        @Override
//        public void run() {
//            while (true){
//                try {
//                    VoucherOrder voucherOrder = orderTasks.take ();
//                    handleVoucherOrder (voucherOrder);
//                } catch (Exception e) {
//                    log.error ("处理订单异常",e);
//                }
//            }
//        }
//    }

    private void handleVoucherOrder (VoucherOrder voucherOrder) {
        Long userId  = voucherOrder.getUserId ();
        RLock lock = redissonClient.getLock ("lock:order:" + userId);
        boolean isLock = lock.tryLock ();
        if (! isLock) {
            log.error ("不允许重复下单!");
            return ;
        }
        try {
            proxy.createVoucherOrder (voucherOrder);
        } finally {
            lock.unlock ();
        }
    }

    private IVoucherOrderService proxy;
    @Override
    public Result seckillVoucher(Long voucherId) {
        Long userId  = UserHolder.getUser().getId();
        Long orderId = redisIdWoker.nextId ("order");
        Long result = stringRedisTemplate.execute (SECKILL_SCRIPT,
                Collections.emptyList (),
                voucherId.toString (),
                userId.toString (),
                orderId.toString ()
        );
        int r = result.intValue ();
        if (r != 0){
            return Result.fail (r==1 ? "库存不足":"同一用户不允许重复下单!");
        }
        proxy = (IVoucherOrderService) AopContext.currentProxy ();
        return Result.ok (orderId);
    }

//    @Override
//    public Result seckillVoucher(Long voucherId) {
//        Long userId  = UserHolder.getUser().getId();
//        Long result = stringRedisTemplate.execute (SECKILL_SCRIPT,
//                Collections.emptyList (),
//                voucherId.toString (),
//                userId.toString ()
//        );
//        int r = result.intValue ();
//        if (r != 0){
//           return Result.fail (r==1 ? "库存不足":"同一用户不允许重复下单!");
//        }
//        Long orderId = redisIdWoker.nextId ("order");
//        VoucherOrder voucherOrder = new VoucherOrder();
//        voucherOrder.setId(orderId);
//        voucherOrder.setUserId(userId);
//        voucherOrder.setVoucherId(voucherId);
//
//        orderTasks.add (voucherOrder);
//
//        proxy = (IVoucherOrderService) AopContext.currentProxy ();
//        return Result.ok (orderId);
//    }

//    @Override
//    public Result seckillVoucher(Long voucherId) {
//        SeckillVoucher voucher = seckillVoucherService.getById(voucherId);
//        LocalDateTime beginTime = voucher.getBeginTime();
//        LocalDateTime endTime = voucher.getEndTime();
//        LocalDateTime now = LocalDateTime.now();
//        if (now.isBefore(beginTime)){
//            return Result.fail("尚未开始秒杀!");
//        }
//        if (now.isAfter(endTime)){
//            return Result.fail("秒杀已经结束!");
//        }
//        if (voucher.getStock() < 1){
//            return Result.fail("库存不足!");
//        }
//        Long userId  = UserHolder.getUser().getId();
////        synchronized(userId.toString().intern()){
////        SimpleRedisLock lock = new SimpleRedisLock (stringRedisTemplate, "order:" + userId);
//        RLock lock = redissonClient.getLock ("lock:order:" + userId);
//        boolean isLock = lock.tryLock ();
//        if (! isLock) {
//            return Result.fail("不允许重复下单!");
//        }
//        try {
//            IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy ();
//            return proxy.createVoucherOrder (voucherId);
//        } finally {
//            lock.unlock ();
//        }
////        }
//    }

    @Transactional
    public void createVoucherOrder(VoucherOrder voucherOrder) {
        Long userId  = voucherOrder.getId();
        Integer count = query().eq("user_id", userId).eq("voucher_id", voucherOrder.getVoucherId ()).count();
        if (count > 0) {
            log.info ("用户已经购买过一次!");
            return ;
        }
        boolean success = seckillVoucherService.update()
                .setSql("stock = stock - 1")
                .eq("voucher_id", voucherOrder.getVoucherId ()).gt("stock", 0)
                .update();
        if (! success) {
            log.info ("库存不足!");
            return;
        }
        save(voucherOrder);
    }
}
